/Engine/Source/Editor/WorldPartitionEditor/Public/WorldPartition/ContentBundle/Outliner/ContentBundleHierarchy.h
Create a linearization of all direct and indirect children of a given item in the hierarchy
virtual void CreateChildren ( const FSceneOutlinerTreeItemPtr & Item, [TArray](API\Runtime\Core\Containers\TArray)< FSceneOutlinerTreeItemPtr > & OutChildren ) const